Automatic telephone system



Nov. 18 7 1,515,951 J. H. HOMRIGHOUS- AUTOMATI TEL HONE SYSTE Filed May 38 1919 2 Sfleets-She? l i li i a A MARE/MA Maw. 18, I

J. H. HOMRIGHOUS AUTOMATIC TELEPHONE SYSTEM Patented Nov. 18, 1924i.

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JOHN H. I-IOMRIGHO'US, OF OAK EARK, ILLINOIS, ASSIGNORTO AUTOMATIC ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

.AUTOMATIC TELEPHONE SYSTEM.

Application filed May 28,

T 0 all whom it may concern Be it known that 1, JOHN H. HOMRIGI-IOUS, a. citizen of the United States of America, and a resident of Oak Park, Cook County, and State of Illinois, have invented certain new and useful Improvements in Automatic Telephone Systems, of which the following is a specification.

My invention relates in general to semiautomatic telephone systems which comprise a. plurality of exchanges interconnected by trunk lines or toll lines. More specifically my invention relates to such a system in which there are a plurality of groups of such trunk lines accessible to an operator in one exchange, each group leading to other exchanges, and in which there is means automatically controlled by the insertion of a plug in a jack by the operator to pick out a particular group of said trunk lines and automatically select an idle trunk in that group.

In systems of the above general character it has been the practice for the opera tor to operate an automatic switch by means of a calling device in order to pick out a particular group of trunk lines leading to a particular exchange.

The object of my invention, therefore, is to provide means for automatically operating said switch without requiring the ma nipulation of a calling device by the operator, said means automatically controlled by the insertion of a plug in a. jack for operating said. switch to pick out an idle trunk line in a particular group leading to the desired exchange.

In the drawings I have shown a selector switch E accessible from a plurality of acks such as the acks J, J and J which switch in turn has access to a plurality of groups of trunk lines leading to other exchanges where they terminate in other selector switches (not shown).

Fig. 1 shows a cord circuit K having access to a plurality of multiple jacks individual to a single trunk line. The callingdevice D. is also associated with this trunk line.

Fig. 2 shows a selector switch E in which the trunk line terminates. Fig. 3 shows a modification of the invention in which the calling device D is associated with a simi lar trunk line to that shown in Fig. 1,

1919. Serial No. 300,277.

except that it is accessible to an automatic switch rather than to an operators cord circuit.

The modification of the invention which is illustrated in Fig. 3 is claimed in my divisional application Serial No. 733,063, filed August 20, 1924.

Referring to Fig. 1, the cord circuit C, of which only the calling end is shown, may be of any approved type and comprises the usual tip and ring talking strands terminating in the plug P, a combined listening and ringing key K and a supervisory relay 2 in the sleeve of the cord circuit. The calling device may be of any well known two wire type, such for example as is shown in British patent to Dicker #29654 of 1910. Associated with the jacks J, J, etc, is an impulsing mechanism 1), which is controlled in its operation by the relays individual to each jack, such as the relays 6, 7 and 8.

I will now point out more in detail, referring to the accompanying drawings, the method of operation. The operator first inserts the calling plug P of her cord circuit into the jack corresponding to the exchange in which the wanted subscribers line terminates, which may be designated by the first digit of the called number or by a prefix such as the name of the office; in either case the operation will be the same. Suppose the operator desires to connect with a subscribers line in the exchange in which the trunk lines leading from the first level of cont-acts in the bank of switch E terminate. Then the operator will insert the plug 1? into the jack J thereby closing at springs 8 a circuit for the line relay 20 in series wit-h relays 2 and 6, as follows: from ground Gr, winding of relay 2, springs 141,

sleeve of plug P, sleeve of jack J, winding of relay 6, springs 3, springs 15, Wind ing of relay 20, to battery. The relay 20 will immediately energize over this circuit and close a circuit for the slow relay 21 from ground through springs 22 and 23, and relay 21 to battery. The. relay 20 also closes a high resistance shunt around the condenser 24 which is connected between a pair of windings of the repeating coil, said circuit extending from the lower side of condenser 24., resistance 25, lower winding of relay 26, springs 27, to the upper sideof the condenser 24. The closure of this shunt circuit, however, has no effect at tlns time as the talking conductors are still open at the springs 28 and 29. The energization of slow relay 21 over the previously traced circuit supplied a ground to the supervisory circuit to light the busy lamp L and others which may be multipled therewith, through springs 30 and 31, grounds the upper winding of the electropolarized relay 26, which relay is arranged so that it will not operate its armature unless the current flowing in both windings is in the same direction, and also prepares a circuit from the back contact of relay 20' through the slow series relay 32 for the vertical magnet 33.

The slow relay 6 individual to the jack 1 is energized over the previously traced cir cuit although. this operation is delayed somewhat by reason of a copper slug with which its core is provided and closes a circuit for the starting relay 9 in the impulsing switch D, as follows, from ground through springs 42 and 43, common conductor 45, winding" of relay 9 to battery, also places ground potential on the first contact 47 in the bank of switch D. Relay 9, upon energizing, closes a circuit for stepping magnet 12, as follows: from ground through springs 35, springs 38, springs 39, winding of magnet 12 to battery, and opens a point in the circuit of the release magnet 11 at springs 36.

The magnet 12, upon energizing, steps the wiper 46 into engagement with the first contact 47 If the first contact is not grounded the magnet 12 will again be energized, since itinterrupts its own circuit at springs 39, tostep the wiper 46 into engagement with the next contact. This operation will continue until a grounded contact is reached. Each time the magnet 12 energizes a circuit is closed for relay 13 at springs 41 which in turn interrupts the circuit of relay 20 to be hereinafter described. Since the first contact 47 is grounded by the energization of relay 6 it follows that relay will be energized as soon as the wiper 46 engages the contact 47, over the following path: From ground through springs 42 and 44, contact 47, Wiper 46, upper winding of relay 10 to battery. Relay 10, upon energizing, closes a holding circuit for itself from grounded conductor 48, through its lower winding to battery, and closes a circuit for the lamp L notifying the operator that she may now manipulate her calling device, also opens a point in the circuit of magnet 12 at springs 38 and by the closure of. springs 40 the slow relay 6 is shorted. which relay, upon deenergizing, opens the circuit of relay 9 to in turn close the circuit of I release magnet 11, as follows: from ground through off normal springs 37, closed on the first rotary step, springs 36, winding of magnet 11, tobattery. The

release magnet, upon energizing, restores the wiper 46 to normal position in the well known manner.

To proceed: Relay 13, upon energizing. interrupts the circuit of line relay 20 at springs which allows the relay to momentarily de-energize each time the relay 13 is energized. Relay 6 being slow acting. maintains its armature in an operated position during the series of interruptions of its circuit, while the relay 2 in the cord circuit. may be slow acting so as to prevent the flashing of lamp L. Each time the relay 20 deenergizes it closes a circuit from ground through springs 22 and 50, winding of relay 32, and the vertical, magnet 33 to battery. The vertical magnet 33 operates in response to this series of impulses to lift the wipers 51, 52 and 53 opposite some level of contacts to which trunk lines extending to the desired oflice terminate, corresponding to the particular jack in which the plug P is inserted. Although the circuits of relays 21 and 32 are interrupted momentarily at each operation of relay 20 both will remain energized during transmission of such impulses and after the impulses cease and relay 20 comes to rest energized, the relay 32 will fall back and relay 21 will remain energized. Since the connection is established by way of jack J the vertical magnet will lift the shaft and wipers 51, 52 and 53 opposite the first level of contacts and as soon as the vertical magnet operates the shaft one step, the off normal springs 54 and close. The springs 55 close the circuit of release magnet 56 at one point and at springs 54 close a point in the circuitof the rotary interrupter relay 57. The circuit of the release magnet 56 is maintained open at the back contact of relay 21. The relay 57, however, energizes as soon as the springs 54 close over a circuit extending from ground through springs 30 and 31 of relay 21, springs 58 and 59 of relay 32, springs 54, and relay 57 to battery. The relay 57, upon energizing, closes a locking circuit for itself at springs 60 extending from ground through springs 60, interrupter springs 61 of the rotary magnet 62, springs 54, and relay 57, to battery, and also closes one point in the circuit of the rotary magnet 62 at springs 63. Now, after the impulses cease, and the relay 32 deenergizes, a circuit is closed for the rotary magnet extending from ground through springs 30 and 31, springs 58 and 64, springs 63, and magnet 62 to battery. The rotary magnet therefore. operates to step the wipers 51, 52 and 53 one step onto the first set of contacts in the first bank level. Another result of the operation of the rotary magnet is to open the locking circuit of the relay 57 at springs 61. The relay 57 will therefore decnmfgize and open a contact in its own locking circuit at springs 60. As soon as the springs (35 open, the rotary magnet will, deenergize and again close springs [31. lirssun'iing now that the trunk line selected is busy, then a ground potential will be found on the private contact with which the; wiper is now in contact. As soon, therefore, as the springs 61 come into contact a new circuit will be closed for the relay 57 extending from ground over the wiper 52, springs ('55 and 66, springs 61, springs and relay 57 to battery. The relay 57 will again operate to close the circuit of magnet 62 and its own circuit to step the wipers to the next contact. This alternate operation of the relay 5? and the rotary magnet cmitiinu-is until. an idle trunk line is reached, at which time no ground will be found upon the private contact and the relay 57 will therefore remain deenergized after the springs 61 are closed. It may be here noted that during the energization of the relay 32 and also during the rotation of the wipers, the relay 67, although in series with the relay 5 7, is maintained short circuited, first by the ground through springs 30, 31, and 59 and during rotation by the ground on the private wiper. The last incmiioined slort circuit extends from ground on wiper springs and 66, relay 6?, springs 30 and 31 to ground. Now, however, when an idle trunk is reached, this short circuit is re moved and the relay 37 which is of high resistance, energizes in series with relay 5'7. The circuit for energizing relay 67 extends from ground through the springs 30 and 31, relay 6'7, springs 61, springs 5 and rela 57 to battery. Tl'ie relay 57 does not ene gize over this circuit on account of the high resistance of the winding of relay 611'. The relay 67, upon energizing, extends the tall;- ing circuit from the windings and 69 of the repeating coil to the wipers 51 and 53, and spring 65 disconnects test wiper 52 from the junction of its own winding and that of stepping relay 5? and connects it instead to the grounded conductor 48, thereby placing a groundpo-tential on the contact engaged by the wiper to prevent seizure of the trunk line by another switch. An-- other result of the energization of relay 6'? is to open the springs 71, thereby preventing any further operation of the operating magnets.

Now, as soon as the relay '6? closes its springs 28 and 29, ashunt circuit is closed across the trunk conductors- 72 and .73 for the double wound line relay of the seized selector switch (not shown) in a second exchange, which extends as follows: iflu-llili conductor 72, wiper 51, springs 28, winding 68 of repeating coil, springs 27, lower winding of relay 26, resistance 25, winding '69 of repeating coil, springs 29, wiper 53, trunk conductor '7 The relay 26 of the eel cut or ll does not energize at this "time as the cmrent in its two windings (lows in opposite directions.

The foregoing operations have all .occurred in response to the insertion of the plug P into the jack J. The operator noticing the lamp L glowing will actuate the calling device key h: which substitutes ground through the calling device C. T). for the ground through the relay 2 in the ci-r cuit of relay 20.

Now, when the operator operates the calling device to send out a series of impulses corresponding to a digit of the called number, the line relay 20 of the selector E will be operated as previously described to re tract and attract its armature a predeter mined number of times. The closure of springs 22 and 50 has no effect at this time due to the springs 71 being held open by relay 67. The opening and closing of springs 27, however, opens and closes the circuit previously traced across the trunk conductors 72 and 73 to in turn operate selector switches and a connector switch (not shown) to thereby establish a connection with a called line. Upon the response of a called subscriber the current flowing in the trunk conductors is reversed in the well known manner, which causes the lower winding of relay 26 to assist the upper wi-iaid'ing. Therefore relay 26 will operate and close a circuit for relay 7 5, at springs 74:. The relay 75, upon energizing, closes a new circuit for the lower winding of relay 26 at springs 76, and places the relay 21 in the circuit of supervisory relay 2 in place of relay 20 which now deenergizes. The relay 21, being of higher resistance than relay 20 causes the marginal relay 2-to fall back and open the circuit of supervisory lai'i'ip L to notify the operator that the calling party has removed his receiver, it being assumed that the: calling device hey K was restored to normal after the last series of impulses was sent in.

Conversation may proceed over the heavy conductors shown in the drawings and when the conversation is completed the switch E may be released by the removal of the plug P from the jack J, thereby opening the circuit of relay 21 at springs Relay '21, upon deenergizing, closes an energizing cir cuit for the release magnet 56, which causes the switch E to restore its shaft and wipers to normal, also removes ground from conducto-r 48, whereupon relay 10 will deenergize, .also the circuits of lamps L and L will be opened.

It will be noted when the plug P is inserted in the jack J" relay 7 will be energized instead of relay 6, which causes the switch I) to step to the second contact, thereby interrupting the circuit :of relay. 20 two times, to in turn raise the wipers of switch E opposite the second level of contacts.

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Likewise the insertion of the plug into jack J causes the switch E to select an idle trunk in the third level.

Referring to Fig. 3, I have shown a trunk line accessible from various levels of a selector switch which terminates in a switch similar to the switch E. Associated with this trunk line is an impulsing switch D which is similar in all respects to the switch D. It is to be understood that the trunk lines 100 and 103 may be accessible from all the levels in the bank of switch or from one level.

When the switch Fis operated to seize the trunk line from a particular level the switch D Will operate to interrupt the op erating circuit a certain number of times corresponding to the contact grounded in the bank of the impulsing switch D.

The selector switch F is of the usual Strowger type of selector switch; only the wipers and line switching relay are shown.

Assume that the trunk line terminals 106, 107, 108 and 109 are seized by the selector switch F. Then as soon as the switching relay 114 is energized a circuit is closed for relay 104 in series with the line relay 20 of switch E (relay 20 corresponds to the line relay 20 of switch E) as follows: from ground through springs 115, wiper 111, contact 107, winding of relay 104, conductor 101, winding of relay 20 to battery. Relay 104, upon energizing places ground potential on the first contact in thebank of switch D, also closes a circuit for the starting relay 9 of the impulsing switch D. The switch D operates ina manner hereinbefore described to open the circuit of line relay 20 one time, whereby the wipers of switch E (not shown) are raised to the first level of contacts in its bank.

The wipers of switch IE will be automatically rotated in the usual manner to pick out an idle trunk line in the elected group which may extend to an operators position in another exchange.

It is not thought necessary to describe the operations of switches D and E in detail, as they are similar to the switches D and E, respectively, and similar reference characters have been applied to like parts. It will be seen that when the trunkis seized from any level in the bank of switch F, the switch E may be operated to one certain level or to a different number of levels corresponding to the number of levels in which the trunk line terminates in the bank of switch F.

Having 'fully described and ascertained my invention in the foregoing specification, what I claim to be new and desire to have protected by Letters Patent will be pointed out in the appended claims.

What I claim as my invention is:

1. In a telephone system, an automatic switch directively controlled to pick out a. groua of lines, a trunk line leading to said switc having a plurality of branches. means for seizing said trunk him via one branch, automatic means responsive to said seizure for automatically operating said switch to pick out a particular group of lines,said last means responsive to the seizure of said trunk via another branch to operate said switch. to pick out a different group of lines.

2. I11 a telephone system, a trunk line having an automatic switch at one end thereof, and multiple terminals at the other end thereof, an impulse sender associated with said multiple terminals, and means controlled by the seizure of each of: said terminals for causing said impulse sender to automatically transmit a different series of impulses over said trunk line to operate said automatic switch.

3. In a telephone system, a trunk line having a plurality of branches, means for seizing any one of said branches, an impulse sender automatically operated in response to the seizure of any terminal, and means associated with each terminal and operating when that particular terminal is seized for predetermining the number of impulses to be sent over said trunk line by said impulse sender.

4. In a telephone system, a trunk line having a plurality of branches, means for seizing any of said branches, an impulse sender common to said branches for sending impulses over said trunk line, a relay individual to each branch, each relay operated when its associated branch is seized to start the operation of said impulse sender and to predetermine the number of impulses transmitted thereby.

5. In a telephone system, a trunk line having a plurality of normally connected. branches, an automatic impulse sender individual to said trunk line, said impulse sender comprising a rotary switch having contacts and wipers co-operating to t.:\11S-- mit impulses over said trunk line, means for seizing said trunk line via any one oi said branches, and means controlled over each branch for causing said rotary switch to transmit a ditlerent number of impulses over said trunk line automatically.

6. In a telephone system, a series of jacks, an automatic switch having levels of bank contacts corresponding to said jacks, a trunk line terminating at one end in said switch and having the other end connected to said jacks in multiple, and means responsive to the insertion of a plug in any jack for auto matically operating said switch to raise its wipers to the corresponding level.

7. In a telephone system, a series of jacks, an automatic switch having levels of bank contacts corresponding to said acks, a trunk line terminating at one end in said switch and having the other end connected to said jacks in multiple, a switch controller individual to said trunk line and common to said jacks, and means for automatically operating said controller responsive to the insertion of a plug in any jack for causing said switch to raise its wipers to the corresponding level.

8. In a telephone system, a series of jacks, an automatic switch having levels of bank contacts corresponding to said jacks, a trunk line terminating at one end in said switch and having the other end connected to said ache in multiple, an impulse sender ass eiated with said trunk line, means for operating said sender automatically when a plug is inserted in any one of said jacks to transmit a series of impulses, the number of impulses transmitted depending on the jack in use, and means for causing said switch to respond to said impulses.

9. In a telephone system, a trunk line having a plurality of branches at one end thereof, an automatic switch at the other end of said trunk line, other trunk lines accessible to said switch and arranged in groups, said groups corresponding, respectively, to said branches a switch controller associated with said first trunk line, means for connecting with said first trunk line via any one of said branches, and means responsive to the completion of the connection for automatically operating said controller to cause said switch to select an idle trunk line in the particular one of said groups which corresponds to the branch in use.

10. In a telephone system, a trunk line having a plurality of branches at one end thereof, an automatic switch at the other end of said trunk line, other trunk lines accessible to said switch and arranged in groups, said groups corresponding, respec tively, to said branches, an impulse sender associated with said first trunk line, an operators link circuit and means for connecting it with any one of said branches, means responsive to the completion of the connection for automatically operating said sender to transmit a series of impulses to said switch, and means for operating said switch responsive to said impulses to select an idle trunk line in the particular one of said. groups which corresponds to the branch in use.

11, In telephone system, a trunk line having a plurality of branches at one end thereof, an automatic switch at the other end of said trunk line, other trunk lines accessible to said switch and arranged in groups, an impulse sender associated with said first trunk line, an operators link cir cuit and means for connecting it with any one of said branches, means responsive to the completion of the connection for automatically'operating said sender to transmit a seeps l W ries of impulses to said switch, means for operating said switch responsive to said impulses to select an idle trunk line in one of said groups, an impulse sender associated with said link circuit, operable to transmit another series of impulses to said switch, and means in said switch. for repeating the second series of impulses over the selected trunk line.

12. In a telephone system, a trunk line having a plurality of branches at one end hereof, means for extending a connection to said trunk line via any one of said branches, a finder switch operated automati ally responsive to the completion of the connection to hunt for and locate the branch in use, means controlled by said finder for transmitting a series of impulses over said trunkline, the number of impulses in the series varying according to the branch in use, and an automatic switch at the other end of said trunk line responsive to said se' ries of impulses.

13. In a telephone system, a trunk line having a plurality of branches at one end thereof, means for extending a connection to, said trunk line via any one of said branches, a finder switch operated automatically responsive to the completion of the connection to hunt for and locate the branch in use, said finder switch being of the step-by-step type, means for transmitting impulses over said trunk line corresponding in number to the number of steps taken by said finder, and an automatic switch at the other end of said trunk line responsive to said impulses.

14. In a telephone system, a trunk line having a plurality of branches at one end thereof, means for extending a connection to said trunk line viaany one of said branches, a finder switch operated automatically responsive to the completion of the connection to hunt for and locate the branch in use, an automatic switch at the other end of said trunk line having a plurality of off normal positions each corresponding to a different one of said branches, and circuit arrangements whereby said finder controls said automatic switch over the trunk line to advance it to the particular position which corresponds to the branch in use.

15. In a telephone system, a trunk line having a plurality of permanently connected branches at one end thereof over which calls may be directed to said trunk, automatic switching mechanism at the other end of said trunk, a variable impulse sender at the branched end of said trunk line for controlling said switching mechanism, means responsive automatically whenever a call is extended to said trunk line via one of said branches for operating said sender, and circuit arrangements for rendering the number of impulses transmitted in any case dependent upon the branch in use.

1.6. In a telephone system, a trunk line having a plurality of permanently connected branches at one end thereof over which calls may be directed to said trunk, automatic switching mechanism at the other end of said trunk, a variable impulse sender at the branched end of said trunk line for controllin said switchin' mechanism rou s of trunks accessible to said switching mecha nism corresponding, respectively, to said branches, and means responsive automatically whenever a call is extended to said trunk line via one of said branches for operating said sender in the correct manner to cause said switching mechanism to select the particular group of trunks which corre sponds to the branch in use.

17. In a telephone system, a plurality of jacks, a trunk line permanently connected in multiple to all said jacks, a switch having a plurality of fixed contacts, one for each jack, and a movable contact, means for causing said switch to advance its movable contact to the fixed contact corresponding to any jack which has a plug inserted therein, an 1111- pulse transmitter actuated automatically to send impulses over said trunk line, the number of impulses transmitted depending on the extent of the movement of said movable contact, and an automatic switch at the distant end of said trunk line responsive to said impulses.

18. In a telephone system, a trunk line terminating in an automatic switch, groups of other trunk lines accessible to said switch, a plurality of jacks, there being a diiferent jack assigned to each of said groups of trunk lines, an impulse sender common to said jacks, a connecting plug, and means responsive to the insertion of said plug in any jack "for causing said sender to operate said switch to connect with a trunk line in the particular group which corresponds to the jack in use.

Signed at Chicago, Cook County, Illinois, this 26th day of May, 1919.

JOHN H. HOMRIGHOUS. 

